Bishop Hill Two worlds collide
Feb 23, 2016 Climate: Models Climate: Statistics GWPF ;)
GWPF have release a very interesting report about stochastic modelling by Terence Mills, professor of applied statistics and econometrics at Loughborough University. This is a bit of a new venture for Benny and the team because it's written with a technical audience in mind and there is lots of maths to wade through. But even from the introduction, you can see that Mills is making a very interesting point:
The analysis and interpretation of temperature data is clearly of central importance to debates about anthropogenic globalwarming (AGW). Climatologists currently rely on large-scale general circulation models to project temperature trends over the coming years and decades. Economists used to rely on large-scale macroeconomic models for forecasting, but in the 1970s an increasing divergence between models and reality led practitioners to move away from such macro modelling in favour of relatively simple statistical time-series forecasting tools, which were proving to be more accurate.In a possible parallel, recent years have seen growing interest in the application of statistical and econometric methods to climatology. This report provides an explanation of the fundamental building blocks of so-called ‘ARIMA’ models, which are widely used for forecasting economic and financial time series. It then shows how they, and various extensions, can be applied to climatological data. An emphasis throughout is that many different forms of a model might be fitted to the same data set, with each one implying different forecasts or uncertainty levels, so readers should understand the intuition behind the modelling methods. Model selection by the researcher needs to be based on objective grounds.
There is an article (£) in the Times about the paper.
I think it's fair to say that the climatological community is not going to take kindly to these ideas. Even the normally mild-mannered Richard Betts seems to have got a bit hot under the collar.
Are @thetimes so desperate for subscribers that they're reduced to covering daft GWPF reports for trashy clickbait? https://t.co/u8VqcNOOJc
— Richard Betts (@richardabetts) February 23, 2016
Reader Comments (109)
"Mark,
Are you off school today, or do you have Wi-Fi access in the classroom?"
(ATTP on Feb 24, 2016 at 12:53 PM).
Oh Ken, what a witty and brilliant put-down - not. Still, thank you for saying it. It is so you, and displays you in your true colours.
No, I'm not at school; I'm retired. That's why it's permissible for me to be using the internet during the working day for my own private purposes (so long as my activities online are legal - which they are).
Apologies for the delay in responding, by the way. Despite being retired, I have other things to do than spend most of my day playing on the internet. I'm perplexed that the same apparently isn't true of you, even when you're supposed to be at work.
Unless your job description includes something along the lines of "spend half of every working day writing articles and making posts on your own narcissistic website and trolling websites which you dislike" it strikes me that you spend a significant proportion of most days not doing your job.
Do your employers know how you spend your working day? Do they approve? If so, I'd be rather concerned about the state of academia these days. If they don't know, I think you're the one who should be concerned (as well as more than a little ashamed and embarrassed).
https://en.wikipedia.org/wiki/Tu_quoque
anonym
If your link is aimed at my criticism of ATTP it's a pretty poor effort. I have said nothing about the substance of his comments. My criticism of his behaviour stands on its own - I think it's wrong for someone who is effectively a public employee (or indeed any employee) to spend a large part of every working day pursuing his own agenda on the internet instead of devoting his time to the employer who is paying him. Do you disagree with me? If so, why?
Mark Hodgson:
No, sorry, it wasn't aimed at your previous comment at all. It was aimed at the several people who have offered criticism of the IPCC models as a defence of Mills'.
Mark Hodgson, you will find "Outreach Work" listed in aTTP's entry at his employer's website.
Quite what this means, I do not know, but if his employers rely on taxpayer funding, it might raise many more interesting questions.
anonym
Fair enough - thanks for the clarification; apologies for getting hold of the wrong end of the stick.
golf charlie - interesting info, thanks.
It looks like Gavin Schmidt conveniently left out HADCRUT4's numbers for 01-16 when temperature returns back down to the range predicted by Mills' model. 12-15 was an outlier month caused by El Nino & Schmidt used it to wrongly suggest Mills' model had failed.
https://twitter.com/PhilWMagness/status/702578231875137536/photo/1
Now some, nor Eli to be sure, might point out that Prof. Mills picked breakpoints by guess and by golly while there are perfectly good statistical methods for doing so. Party like starting the global temperature analysis in 1997 again, we can.
If you don't deal off the bottom of the deck, you get this
https://quantitare.files.wordpress.com/2016/02/hadcrut_projection.png?w=660 (from jimt@ https://andthentheresphysics.wordpress.com/2016/02/23/the-gwpf-is-funny/#comment-73345
with three breakpoints instead of 5. Mills fifth breakpoint at 2002 for HADCrut determines his result, the rest is just numerical drivel.
Drivel it might be but it is not noticeably worse than the GCM outputs.